VCCA Home Forums TECHNICAL - GENERAL Trucks and Vans brake pedal return spring

Hi all. I've tried to figure out where the end of the brake pedal return spring goes on my 46 1/2 ton truck. I'm pretty sure one end goes on the shoulder of the master cylinder linkage bolt, but the spring is stiff and can't go far. I took this off many years ago and believe I must be missing some link or something. Any help would be great. Thanks Tim

Tim,
The parts catalog says the same spring is used on all '36-'46 1/2 ton as well as '36 1-1/2 ton. I looked under my '36 1-1/2 ton and found the spring hanging from the head of a cotter pin in the crossmember behind the master cylinder.
The front hook is broken off my spring and none of the clevis pins at the master cylinder have a double head as is sometimes found. However one of the pins has a wire instead of a cotter pin so I suspect that the return spring was originally hooked there. The spring would have to stretch to about 5-1/2 inches to hook there. The catalog says the free length is 3-5/16 inches. That seems like a lot of stretch to me.
I just noticed a larger spring on my truck. It hooks to a hole on the end of the linkage lever and to a hole in the aforementioned crossmember.
Both of these springs are listed, in the catalog, as being the same for my truck and yours.

Mike

Thanks Mike.
I really appreciate you looking under your truck for me. I reread every chat site I could find relating to this pedal return spring. On the stove bolt site (long time fan) I found a description I'd missed. Someone was smart enough to know there was a diagram that shows all this in the owners manual. This shows a hole in the pedal itself for the spring. My pedal has no hole. So with a long wire link, I'll be fine. Thanks again for the help.
tim

Tim,

On my 40 1/2 ton pickup, which is close to 100% original, the brake pedal return spring is connected with a double-hook wire extension link about 7 or 8 inches long, made of approximately .090" wire. One end of the extension hooks on the shoulder under the head of the master cylinder clevis pin bolt. The other end of the extension connects to one end of the spring. The other end of the spring hooks to an offset bracket that is bolted to the rear of the engine splash pan.

I may be able to get a photo of it if you'd like.

Mark

Thanks Mark
This makes sense. I don't have my splash pans straightened out, but may need to do this sooner than later. ( I thought these were a luxury I could add any time) . I used heavy piece of wire (rod) to make a link last night and the problem was it is up against the throw out arm if I hook it on the same support bracket the clutch spring is hooked on to . Being able to raise it up, and keep it straight in line with the master cylinder (where there is now nothing) will make the difference. Really appreciate the help.
Tim

Tim,

Here's a photo of the brake return spring on my 40 1/2 ton. As you noticed, the reason for the extension link is that if the spring were connected directly to the master cylinder clevis bolt, it would interfere with the clutch fork. In the photo, you can clearly see the offset bracket that the spring connects to. The bracket gives the spring and extension a good lead to the master cylinder clevis bolt so the extension runs under the clutch fork, but doesn't interfere. If you don't have the offset bracket, you could probably make one very easily from 1/8" X 3/4" steel flat bar.

The extension link is 7", hook-to-hook, and the offset bracket reaches forward 2-3/4" from its attachment to the back of the splash pan. Not visible in the photo is a lip on the mounting foot of the offset bracket that contacts the bottom edge of the splash pan stiffener bracket and causes the offset bracket to tilt inward slightly to properly position the spring and link for a straight shot back to the master cylinder clevis bolt. If you have to fabricate your own bracket, you could do without the lip.

Mark





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Mark, Thank you. The picture and measurements are just what I needed. It simplifies everything to keep the spring out in the open. I found my splash pans and got the left one ready for paint. I'll try and get this on in the next few day so I can finally bleed and adjust my brakes.
I really appreciate you getting me back on track.
Tim

I dont have the splash pans on at this time but my clutch return spring is attached to a bracket that bolts on the bellhousing,my 37 is a combination of many years of parts and I had to go with a 38 to 46 bellhousing to use the newer style clutch on my 37. I took everything off a 41 1/2 ton that was in a local junkyard and it had the clutch return spring bracket on it so I presume its original,I think that bracket also has a place for the brake spring too.

I went out in the garage and looked at the 37 and both the brake and clutch return springs attach to the bracket,its like a half S and bolts to the front lower edge of the bellhousing with two bolts and looks like I need to get the correct brake return spring since the one I have on it rubs the clutch fork. The original 37 bellhousing had the holes for that bracket along with the 41 bellhousing it came off of and I now have a 47 to 53 bellhousing and it has the holes in the same spot so I presume 37 and up had that bracket for the springs which probably was easy to loose when the clutch was replaced and the springs stuck elsewhere. I still have the bracket for the splash pans and looks the the bracket will not hit the splash pan.